1. Field of the Invention
The invention relates to a hydraulic circuit for supplying a plurality of series-operated consumers of a hydraulically controlled installation, in particular of an injection molding machine, having a pump with feed-flow pressure control.
2. Description of the Related Art
In a hydraulic circuit of this type, such as is used in injection molding machines, the individual consumers, for example the injection unit, the extruder, the clamping unit, the ejector, etc., are customarily supplied serially by a pump with feed-flow pressure control. Check valves are placed upstream of the individual consumers, which are opened selectively and, as a rule sequentially, for activating the respective consumer.
Accordingly, inflow control takes place in such a hydraulic circuit, by means of which a slow-down of a consumer, i.e. of the mass moved at this consumer, is impossible from a structural point of view without additional expenditures for valves. For this reason it is necessary to provide additionally a proportional valve at consumers of this type, in particular consumers of high mass, such as the clamping unit or possibly the ejector. This complicates the structure of the hydraulic circuit and the control circuitry.